1. Welding Procedure Specification (WPS) to be followed for the welding to be qualified and the Procedure qualification record (PQR) is approved before start of welding.
2. Approved brand of electrodes are used for welding.
3. Physical properties of the weld produced by an electrode shall not be less than minimum value of base metal.
4. Electrode qualification and batch record are maintained.
5. Each pipe shall be thoroughly checked internally & externally for visual defect/ damage and cleaned internally by compressed air blowing.
6. Damaged end shall be cut and re-bevelled with beveling machine.
7. All new bevels shall be 100% dye penetrant /MPI tested and Ultrasonically tested for any lamination.
8. Use of internal clamp is mandatory for pipe dia.> 10” except tie in joints, fitting etc. In such case external clamps are used.
9. Each joint shall bear an identification number which shall be followed for NDT.
10. The number of welders, and welding sequence, speed etc. should be similar to that of adopted in approved welding procedure.
11. Radiography examination of 100 % girth weld is carried out.
12. Weld shall meet the requirement of API 1104.
13. In addition 100% ultrasonic inspection is required for critical weld joints i.e. tie in, welding of valves etc. joints which have not undergone pressure testing i.e. GOLDEN TIE-Ins.
14. Repair is limited to maximum 30% of the weld length.
15. Weld containing cracks shall be cut and re-bevelled to make a joint.
16. Destructive testing of weld joints are done for 0.1% of the total numbers of welds completed.